A retrospective study on potential cross-reactivity between hypersensitivity reactions to taxanes and fosaprepitant.

Abstract

e24098 Background: Hypersensitivity reactions (HSRs) to taxanes are often linked to their solvents: Cremophor EL in paclitaxel and polysorbate 80 in docetaxel. Fosaprepitant, an antiemetic containing polysorbate 80, is rarely associated with HSRs ( < 1%). After observing two patients who developed HSRs to both fosaprepitant and taxanes, we conducted a retrospective review of our cancer center database to assess the incidence and relationship of HSRs between these drugs and patients’ allergy histories. Methods: Patients treated with paclitaxel, docetaxel, and/or fosaprepitant at Maimonides Cancer Center between August 1, 2017, and July 31, 2021, were identified through electronic medical records. Data collected included demographics, documentation of HSRs, history of allergies to medications or food, and chemotherapy history. Fisher's exact test was used to assess the significance of differences between the groups. Results: A total of 2063 patients received treatment with taxanes and/or fosaprepitant. Of these,1642 received fosaprepitant, 1336 received one or both taxanes, and 915 received both fosaprepitant and taxane. Overall, 37/1336 (2.76%) developed taxane HSRs, including 30/922 (3.25%) to paclitaxel, and 7/413 (1.69%) to docetaxel. In a subset of the above cohort, which included patients treated by author YX who documented all HSRs, the HSR rate was 20/232 (8.62%). Notably, only 34 of these patients were treated with albumin-bound paclitaxel as their subsequent treatment and all of them tolerated it well. Among 915 patients who received both fosaprepitant and taxanes, 9 (0.98%) developed HSRs to fosaprepitant, 23 (2.51%) to taxanes, and 3 (0.3%) to both drugs. In patients with fosaprepitant HSRs (N = 9), the incidence of taxane HSRs was 33.3%, compared to 2.08% in those without a reaction to fosaprepitant (p = 0.001), true for either docetaxel HSRs (50% vs 1.5%, p = 0.036) or paclitaxel HSRs (28.5% vs 2.48%, p = 0.014). Similarly, in patients with taxane HSR, the incidence of HSRs to fosaprepitant was 13%, compared to 0.6% in those without a taxane reaction (p = 0.001). Furthermore, Patients with taxane HSRs were more likely to have prior food or drug allergies (56.5% vs. 26.3%, p = 0.003), while fosaprepitant HSRs were not significantly associated with prior allergies (44.4% vs. 27.4%, p = 0.27). Conclusions: HSRs to fosaprepitant are rare, and reactions to both fosaprepitant and taxanes are even rarer. Patients with fosaprepitant HSRs are more likely to develop taxane HSRs and vice versa. This increased HSR rate was seen with both paclitaxel and docetaxel groups and patients with taxane HSRs had a higher prevalence of prior allergies. While these results cannot rule out a cross-reactivity, it suggests that some individuals have an inherent tendency for hypersensitivity which results in developing multiple HSRs.